If the numbers which are divisible by 3 from 1 to 61 are arranged in descending order, then which numbers will be at the 7th and 17th positions from top?

A girl counted in the following way on the fingers of her left hand: She started by calling the thumb 1, the index finger 2, middle finger 3, ring finger 4, little finger 5 and then reversed direction calling the ring finger 6, middle finger 7, and so on. If she counted up to 1994, on which finger did she end her counting?

For an infinite geometric progression a, ar, ar2, ar3, ... if the numerical value of common ratio |r| < 1, then the sum to infinity S∞ will be: